You can use Nofence in sheltered areas like barns, but we recommend you use Shelter beacons to create a safe zone inside buildings where your livestock won't receive audio warnings or pulses.
Roofs on barns and sheds can interfere with GPS signals. When signals bounce off a roof, the collar may log an inaccurate position.
The beacon connects to collars via Bluetooth. When a collar is in range, the GPS receiver switches off and the collar is marked as being in a safe zone.